Posts TaggedDriverScanner 2013
The vast majority of people upgrading will not have any issues, but there is always that stray use-case scenario that will encounter an error. In the past, Microsoft has done a great job with compatibility, and even shown that they are willing to make their OS backwards-compatible with older hardware and as much of the software as possible.
With that said, one of the biggest issues that can bite end-users is driver problems. A printer here or audio card there can wreak havoc with what you assume will be a simple upgrade.